Remote settable fuzes have been used in projectiles for some time. A remote settable fuze allows external information to be input to the projectile before firing. One known method for inputting information to the fuze is by non-contact inductive coupling. This is a transformer approach with the primary of the transformer placed outside the projectile, in what is commonly called a setter, and the secondary of the transformer placed in the fuze. Magnetic flux passes between the primary and secondary with appropriate AC modulation containing data. The information input to the fuze relates to a fuze mode setting or for example, may contain a time-to-burst for the projectile. Time-to-burst represents a predetermined time period after firing, approximating a desired range, after which the projectile detonates.
In a bursting munitions scenario, the most important features of the projectile and its fuze are accuracy and safety to the user. These factors are related to fuze control functions. Previously, systems have used expensive and complicated mechanical and/or electrical methods to try to more accurately determine the range of a projectile and control the fuze. One variable which greatly affects the accuracy of the range determination is the actual muzzle velocity, which can vary depending on a large number of known factors. It has always been desirable to control the detonation of a projectile based on a determination of actual muzzle velocity. However, an accurate system for determining muzzle velocity within a projectile has not been available. Systems mounted directly on the muzzle of specialized guns do exist, but greatly complicate the gun and are contrary to a general standardized approach for all weapons.
Prior systems have depended on time setting and have not been able to accurately predict muzzle velocity. Other fuzing systems require mechanical settings by the user for communicating functions. This dependency on the operator creates a much larger risk of mistake or accident. Other electronic systems have proved to be too costly and require more space in the projectile than is available. Also, some prior solutions use parts, such as crystals, which cannot readily tolerate the forces or shock which the projectile experiences.
Consequently, a need remains for a compact, simple multi functional sensor that acts as a remote receiver and provides more accurate detonation of the projectile.